GB407690A - Improvements in the manufacture of yarn - Google Patents

Abstract

407,690. Spinning yarn directly from slivers of bast and long-leaf fibres. STONE, M. B., Canton Avenue, Milton, and WILLIAMSON, W. P., Ludlow, both in Massachusetts, U.S.A. June 20, 1932, No. 17473. Convention date, June 20, 1931. [Classes 120 (ii) and 120 (iii).] Yarn is made from slivers of bast fibres, such as flax, hemp, jute, and ramie, and of long leaf fibres, such as sisal and manilla, without converting the sliver into roving, by drawing the sliver in a spinning-frame without the use of gills and subjecting it to two or more slip-draft devices between the feed rollers and the drawing rollers so that it is supported at intervals of less length than the average staple, at least two devices being arranged to operate in succession on the sliver. One of the slip-draft devices is arranged near the nip of the delivery rollers so as positively to feed thereto fibres which are not in the grip of either the feed or delivery rollers. In the case of slivers containing extremely short fibres the natural cohesion of the fibres is increased without subjecting the sliver to twist as in a roving frame, for example by crimping the sliver. One slip-draft device comprises a pair of rollers of which one is driven and the other positively driven therefrom and so arranged as to be capable of movement relative thereto, and one of the devices may be constructed so as to effect a drag on the sliver. The apparatus shown is particularly suitable for jute, crimping being effected as the slivers are delivered from a gill box 4, Fig. 1, by means of a weight 8 which fits a guide channel and is periodically raised by the accumulating sliver delivered by rollers 9 ; alternatively fluted delivery rollers in pressure contact may effect the crimping. The crimped sliver 1, Fig. 4, is led from cans 10 to the drawing-rollers of a spinning-frame, the crimping being removed or equalized by an adjustably weighted or spring- controlled lever 14<a> and a conductor 14, or by a pair of rollers rotating at a slightly lower speed than that of the retaining rollers 15, or by a plain bar imposing a drag on the sliver. The slip-draft devices comprise fluted rollers 19, 19<a>, the roller 19 being positively driven and the roller 19<a> driven therefrom, in conjunction with a guide plate or trough 20 and a co-operating weight 20<a>. The roller 19<a> is mounted in a lever 21 so as to be capable of moving independently to and from the roller 19 but at all times remaining in gear. The distances between the nips of the devices 19, 19<a> and 20, 20<a>, and the rollers 19, 19<a>, and the drawing- rollers 16 are less than the average length of the fibres, and the speed of the roller 19 is greater than that of the feed rollers 15. The lever 21 may be held up by a hook to facilitate threading after breakage and when starting.